Of 227 potroom workers studied, 7% had symptoms consistent with occupational asthma. [Malo] In Norway in recent years, the annual incidence of potroom asthma has been about 1.5% of exposed workers. The most common presentation is a late asthma attack occurring several hours after finishing work. [Sjaheim T, et al. Airway inflammation in aluminum potroom asthma. Occup Environ Med 2004;61:779-785] "Among aluminum smelter workers, the impact of a 30-year working career with particulate exposure at the permitted level was about the same as smoking 75 grams/week (or about 1/2 pack of cigarettes per day). [Rosenstock, p. 324] Potroom workers have an increased incidence of asthma that is associated with exposure to gaseous fluoride. [PMID: 16531831] See the agent "Aluminum production."